US 3517397 A
Description (OCR text may contain errors)
June 30, 1970 s. G. MOORE 3,517,397
POWERED RETRAC'IING BED CONSTRUCTION Filed Feb. 25, 1968 6 Sheets-Sheet 1 INVENTOR.
STEPHEN G. MOORE ATTORNEYS June 30, 1970 s MOORE 3,517,397
POWERED RETRACTING BED CONSTRUCTION Filed Feb. 23, 1968 6 Sheets-Sheet 2 FIG. .2
INVENTOR. STEPHEN G. MOORE 5 M ,aiw m ATTORNEYS June 30, 1970 5, MQQRE 3,517,397
POWERED RETRACTING BED CONSTRUCTION Filed Feb. 25, 1968 6 Sheets-Sheet 5 5' 5 ,3? "4a 1 4H 5 l 37 INVENTOR. STEPHEN G. MOORE BY I fie I fivU vgw wam 1W P ATTORNEYS June 30, 1970 5, MOORE 3,517,397
POWERED RETRACTING BED CONSTRUCTION k Filed Feb. 25, 1968 6 Sheets-Sheet 4 Ax Q/L' 77/7 7/ Y/ O 78 FIG. 8
F IG. .9 7
INVENTOR. STEPHEN-G. MOORE -J BY I I 3'1" m Hul -If: 4' XIMPIO ATTORNEYS United States Patent 3,517,397 POWERED RETRACTING BED CONSTRUQTION Stephen G. Moore, 461 Nevada, Palo Alto, Calif. 94301 Filed Feb. 23, 1968, Ser. No. 707,685 Int. Cl. A47c 17/40 US. Cl. ---l47 18 Claims ABSTRACT OF THE DISCLOSURE The head end of a bed engages with steeply inclined guides and with a motor driven lead screw which raises the head end along the guide means while drawing the foot end towards the base of the guides. Mechanism is provided to support the weight of the raised bed to avoid a reactive force on the motor, the mechanism acting automatically to facilitate an initial outward movement of the foot of the bed when the motor is energized to lower the bed.
BACKGROUND OF THE INVENTION This invention relates to folding beds and more particularly to simplified, reliable and safe motor operated retracting mechanism which moves a bed between a substantially upright position and a lowered position with a minimum of manual effort.
Folding beds of the class which can be retracted to an upright position against a wall offer many advantages when used in certain types of dwelling. Notably, a folding bed provides for more efficient utilization of building space and provides greater flexibility in the use of a room. Accordingly, folding beds are extensively used in apartments, cabins and the like where floor space may be restricted. Further, folding beds are often useful in more spacious residential buildings in order to provide accommodations for occasional guests.
Although the advantages of folding beds are considerable, usage has been somewhat restricted by certain problems. A very significant factor which has limited the use of such beds is that the constructions which have heretofore been available commercially require considerable manual effort in connection with raising and lowering of the bed. Many potential users dislike the taxing physical effort involved in these operations and some other potential users, such as invalids, children and elderly persons may be incapable of operating the conventional folding bed at least without great difficulty.
Further considerations which have caused some resistance to more widespread use of conventional folding beds include a tendency towards jamming and other malfunctions, the possibility of minor injuries to persons manipulating the bed and excessively elaborate and costly constructions. Further, bending of certain structural members and rapid wear at pivot joints is a common characteristic of conventional folding bed designs. In addition, many folding bed constructions are highly conspicuous even in the retracted position and this is often a very significant factor in resistance to the use of such beds in situations where they might otherwise be very desirable.
In order to resolve some of these problems, attempts have heretofore been made to motorize the raising and lowering of a retractable bed. The constructions employed have not fully met all the problems discussed above. In general, complex and bulky lift mechanisms have been needed and this is undesirable from the standpoint of cost, appearance and maintenance requirements. For example, a typical prior motor driven bed operates by pivoting the foot end of the bed upwardly toward the Wall. This inherently requires complex mechanism. In addition, high stresses are generated in certain portions of the mechanism necessitating massive construction and often a high torque motor or mechanism providing for mechanical advantage at the expense of rapidity. Further, the motor drive mechanism may be required to support much of the Weight of the elevated bed and this also necessitates structural complications.
SUMMARY OF THE INVENTION The present invention is a retractable bed construction which may be raised or lowered without significant manual effort and which may be of a simple, durable, inconspicuous and safe construction thereby alleviating the several problems hereinbefore discussed.
The invention provides guide means and a motor drive which are generally disposed at a wall, to lift an adjacent end of the bed while drawing the opposite end of the bed toward the base of the guides whereby the bed assumes a near vertical position. Reversal of the motor lowers the bed in an opposite manner. In a preferred form, ramp mechanism is provided which supports the lower end of the raised bed to avoid sizable reactive forces on the lift system, the mechanism acting automatically to release the bed and to facilitate initial downward and outward movement of the lower end of the bed when the motor is reversed. The invention further provides for retaining the mattress on the bed in the course of these movements and for concealing the lift mechanism when the bed is in its lowered position.
Accordingly it is an object of this invention to provide for greater ease of operation of retracting beds and to provide an efficient, reliable, attractive, safe and economical construction therefor.
The invention, together with further objects and advantages thereof, will best be understood by reference to the following description of preferred embodiments in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:
FIG. 1 is a perspective view showing a folding bed embodying the invention with the bed being illustrated in the lowered position;
FIG. 2 is a side elevation view showing the bed of FIG. 1 in the raised or retracted position;
FIG. 3 is a frontal elevation view of the power lift and guide means associated with the bed with the bed being removed for clarity of illustration;
FIG. 4 is a fragmentary section view taken along line IV-IV of FIG. 3 further illustrating guide means associated with the bed;
FIG. 5 is a fragmentary section view taken along line V-V of FIG. 3 illustrating details of the lift mechanism;
FIG. 6 is a side elevation view taken along line VI-VI of FIG. 3 showing additional components of the lift mechanism and schematically showing electrical circuitry associated therewith;
FIG. 7 is a plan view of a rocking ramp mechanism which guides and supports the foot of the bed during certain stages in the operation thereof;
FIG. 8 is a broken out side elevation view of the ramp mechanism of FIG. 7 as it appears when the bed is in the lowered position;
FIG. 9 is a broken out side elevation view of the ramp mechanism of FIGS. 7 and 8 as it appears when the bed is in the retracted or raised position;
FIG. 10 is a side elevation view of the bed with a portion of the bed frame broken away further illustrating means for retaining the mattress on the bed during retraction thereof;
FIG. 11 is a side elevation view of a second embodiment of ramp mechanism for supporting and releasing the raised bed;
FIG. 12 is a second side elevation view of the modified ramp mechanism of FIG. 11 showing the changed positions of elements of the structure when the bed is raised;
FIG. 13 is a side elevation view of still another modified mechanism for supporting and releasing the raised bed; and
FIG. 14 is a side elevation view of a fourth embodiment of mechanism for supporting and releasing the raised bed.
DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings and more particularly to FIG. 1 thereof, the invention is adaptable to beds of any various sizes and types, a single bed 11 having a box spring 12 and superajacent mattress 12 being employed in the present example. Spring 12 and mattress 13 may be carried on a conventional rectangular bed frame 14 which includes parallel side members 16 having an angled crosssection to receive the lower outside edges of the box spring. The bed 11 in this example further includes a rectangular foot board 17 and head board 18 which is of specialized construction as will hereinafter be described. The head end of the bed is supported, while in the lowered position, by a pair of legs 19 each having an upper end pivoted to a separate one of the bed frame side members 16. To facilitate the raising and lowering of the bed, the foot end has a pair of spaced apart legs 21 each carrying a roller wheel 22.
As will be evident, it is possible to dispose the bed 11 in a room in any of various arrangements while adapting the invention thereto. However, it is usually preferable to situate the head end of the bed adjacent a wall 23. For optimum concealment and for other reasons to be hereinafter discussed it is particularly desirable, if possible, to situate the head end of the bed in a rectangular alcove 24, which ideally should be somewhat broader than the width of the bed to facilitate access and to provide for the storage of pillows and the like. With this arrangement, a door 26 may be used to close the alcove 24 and completely conceal the bed when not in use.
Referring now to FIG. 2 in conjunction with FIG. 1, the head end of the bed in its lowered position is spaced a small distance from the adjacent wall, which in this instance is the rear wall 23' of alcove 24, and a lift mechanism housing 27 is situated therebetween. Housing 27 in this example includes vertical side members 28 spanned by a top member 29 and an upright back member 31 at Wall 23'. In order to conceal the mechanism within the housing 27 when the bed is in the lowered position and to add to the general attractiveness of the assembly, automatically operated means are provided to cover the front of the housing at such times. Specifically, and as shown in FIG. 2 in particular, a shade roller 32 extends between housing side members 28 immediately below top member 29 and near the edge thereof which is remote from wall 23. Roller 32 may be of the known spring-loaded type which carries a fabric shade 33. The lower end of shade 33 is attached to the adjacent end of the bed 11 whereby the shade is automatically withdrawn from roller 32 as the bed is lowered and is automatically rewound on the roller as the bed is raised. In order to conceal the edges of the shade 33 and the roller 32, an inwardly directed lip 34 is provided along housing members 28 and top member 29 at the edges thereof remote from the wall 23'.
Considering now the mechanisms for raising and lowering the bed, with reference to FIGS. 2 and 3 in conjunction, a pair of spaced apart parallel linear guide tracks 36 are situated within housing 2 7 to guide the head end of the bed between its elevated and lowered positions. Each of the guide tracks 36 is inclined relative to wall 23' at a small angle for purposes which will hereinafter be discussed, an inclination of about eight to ten degrees from vertical being typical, the lower ends of the guide tracks being spaced outwardly from the wall to provide the inclination.
In order to couple the head end of the bed to each of the guide tracks 36, a guide member 37 is engaged in each thereof and is slidable therealong. As shown in FIG. 4 the guide tracks 36 may have a hollow rectangular crosssection with a linear slot 38 extending along the side of the guide tracks which faces the head of the bed. Guide members 37 extend into the slot 38 and are held therein by rollers 39. Brackets 41 extend from the frame member 42 at the head of the bed and are pivotally coupled to the guide members 37 by means such as a bolt 43.
The engagement of the head end of the bed 11 with guide tracks 36 as described above provides for movement of the bed between the lowered position illustrated in FIG. 1 and the raised or retracted position illustrated in FIG. 2 wherein the head end of the bed has been lifted along the wall 23' and the foot end has been drawn towards the wall. To accomplish this raising and lowering movement without any substantial manual elfort, motor drive means are provided, such means being best illustrated in FIGS. 3, 5 and 6 in conjunction.
In the present example, the drive means is comprised of a third linear guide track 44 situated midway between the guide tracks 36 in parallel coplanar relationship thereto and having a similar inclination relative to the wall. As best shown in FIG. 5 in particular, the third guide track 44 again has a hollow rectangular cross-section with a slot 46 extending along the side which faces the bed 11. A threaded rotatable lead screw 47 extends within the guide track 44, the lead screw being parallel to the guide track and to slot 46 thereof. A lift carriage member 48 extends into the slot 46 and has an internally threaded inner end 49 engaged on the lead screw whereby rotation of the screw moves the carriage upward or downward along center track 44 according to the direction of screw rotation. A bracket 51 extends from the frame member 42 at the head of the bed and is coupled to carriage 48 by means such as a bolt 52 which provides for pivoting motion of the bracket relative to the carriage member. Thus as the carriage member 48 travels up or down along center guide track 44, the head end of the bed 11 is carried with it to raise or lower the bed as hereinbefore described.
Referring now to FIGS. 3 and 6, the lead screw 47 is driven by an electrical motor 53 which is connected thereto through a speed reducing gear box 54 and coupling 56. To accommodate these components the center guide track 44 is terminated a small distance above the floor 57 and is supported at the lower end by a bracket 58 which is secured to a pair of spaced blocks 59 situated on opposite sides of the center line of the lead screw. In this example, motor 53 is mounted on gear box 54 which is in turn disposed between blocks 59 and secured thereto by cross bolts 61. To provide for manual operation of the bed if a power failure should occur, gear box 54 is preferably of the type having an alternate power output. A flexible coupling and socket 55 may be provided at the alternate output to provide for manual turning of the mechanism by a long crank 60.
Referring to FIG. 6, motor 53 is reversible and preferably of a type which develops high starting torque. Such a motor 53 may typically have three leads 62, 63 and 64 and will operate in a first rotational sense when power is applied across leads 62 and 63 and in an opposite rota tional sense when power is applied across leads 62 and 64. To provide for selective reversing of the motor to raise and lower the bed, the common lead 62 may be connected to one terminal of a suitable power source, typically 60 cycle, 110 volt, alternating current as available in most residences, and a two-position control switch 66 provides for alternately coupling the other side of the power source to lead 63 or lead 64. For safety purposes a fuse 67 may be connected between the switch 66 and power supply. The manually operated control switch 66 is situated where it will be within convenient reach of an operator. In this example and as shown in FIG. 1, the switch 66 is mounted on one side wall 28 of housing 27. This location of the switch 66, inside alcove 24, provides a safety feature if a door 26 is used to close the alcove when the bed is in the raised position. In particular, it is not possible for someone to turn the switch to the lowering position while the door closes the alcove, this being a situation which could otherwise result in damage.
Referring again to FIG. 6, further circuit components are provided to avoid any necessity for again operating the switch 66 to stop the motor when the bed reaches either its uppermost or lowermost position. If the motor continued to be energized after the bed reaches either of its extreme positions stalling and possible damage could occur. Accordingly, upper and lower limit switches 68 and 69 respectively are connected between the switch 66 and leads 64 and 63 respectively. As shown in FIG. 3 the limit switches may be disposed along one of the guide tracks 36 in positions where they are contacted and operated by one of the moving elements associated with the bed, such as a guide member 37, when the bed has reached its upper or lower limit of travel. Using the above described circuit connections, both limit switches 68 and 69 should be of the normally closed type and may be of any of various forms known to the art such as microswitches operated by a trip lever, mercury switches or reed switches operated by a magnetic actuator associated with the moving element.
Referring now again to FIG. 6, it may be seen that when the bed is in the lowered position and the control switch 66 is manipulated to energize motor lead 64, the normally closed condition of the upper limit switch 68 will provide energization through motor lead 64 which causes the motor 53 to rotate lead screw 47 to raise the head end of the bed. When the bed reaches its uppermost limit of travel upper limit switch 68 will be opened as hereinbefore described thereby breaking the circuit and de-energizing motor 53. Once the bed commences to move upward the lower limit switch 69' returns to its normally closed condition so that when the control switch 66 is later operated to energize the motor through lead 63 the motor will be operated in a reverse direction to lower the bed with the motor operation eventually being terminated automatically by opening of the lower limit switch 69. The switch conditions at this point, i.e. when the bed has been lowered and the motor 53 has been automatically stopped are those depicted in FIG. 6. It will be apparent that other circuit arrangements are possible to achieve the desired result including low voltage systems and battery operated systems where this may be necessary.
Considering now a very significant and highly advantageous aspect of the invention, with reference initially to FIG. 2, a pair of rocking ramp assemblies 71 are provided to coact with the rollers 22 at the foot of the bed. As will hereinafter be described in greater detail, ramp assemblies 71 function to support much of the weight of the bed 11 in its raised position and then facilitate the initial downward movement of the bed by carrying rollers 22 outward from wall 23 at such times. The ramp assemblies 71 shift automatically, to serve these two functions, in response to forces which are inherent in the above described mechanism.
It may be seen that if no ramps of any kind were present to receive the rollers 22, then a problem is encountered in that the initial force on the rollers as lowering of the bed commences is almost directly downward. The result would be an undesirable jerking movement or possible stalling of the motor or damage to structural members unless the operator were required to manually pull the lower end of the bed outward at this time. If, on the other hand, a simple steeply inclined fixed ramp is employed to avoid this problem, another difliculty is encountered. In particular, much of the weight of the bed remains suspended from the lift mechanism when the bed is in the raised position. The lead screw and motor may then be turned by the weight, when the motor is de-energized, so that it is unable to hold the bed in the elevated position. The ramp assemblies 71 of the present invention shift automatically to support the elevated bed and thereby avoid any sizable reactive turning force on the lead screw at such times.
Referring now to FIGS. 1 and 3 in combination, each of the ramp assemblies 71 is disposed adjacent a separate one of the side guide tracks 36 in alignment with the path of travel of one of the roller wheeels 22 which support the foot end of the bed. The two ramp assemblies 71 are similar, the detailed construction and operation of a representative one of the assemblies being shown in FIGS. 7, 8 and 9.
Referring now to FIGS. 7, 8 and 9 in combination, each ramp assembly 71 has a pair of spaced apart parallel bracket members 72 disposed with one end adjacent the wall 23 and having opposite ends which are of progressively diminishing height in a direction outward from the wall. A rectangular spacer block 73 is disposed between brackets 72 adjacent wall 23' and the brackets are spanned by a relatively short top plate 74 situated above the block 73. Brackets 72 serve as a support and guide means for a curved rocker 76 which is situated between the brackets.
Unwanted motion of the rocker 76 is prevented by the brackets 72 in that short axles 77 extend from each side of the rocker into a substantially elliptical opening 78 in the adjacent bracket. The openings 78 are larger than the axles 77 and are situated with the long axes of the openings at an angle, typically about 45 degrees, with respect to horizontal and with the lowermost portion of the opening being closest to the wall 23. The precise configuration and placement of the openings 78 is determined -by the limits of the desired rocking motions of the rocker 76 and the curvatures thereof as-hereinafter described in greater detail.
The described arrangement of the axle 77 and opening 78 provides for a rocking movement of rocker 76 between a lowered position illustrated at FIG. 8 and a raised position illustrated in FIG. 9. For this purpose the undersurface 79 of the rocker 76 is curved with the curvature being minimal at the tip of the ramp remote from the wall 23 and being of a progressively increasing curvature towards the opposite end of the ramp. The upper surface 81 of the rocker 76 is a ramp surface which is curved in a generally similar manner except that the rate at which the curvature increases towards the back of the rocker is greater than that of the undersurface. Thus the rocker as a whole has a arcuate wedgelike shape.
Thus the axles 77 and openings 78 do not provide the primary support for the rocker but serve to define the limits of the rocking motion against the floor. For purposes which will be hereinafter discussed, the rocker 76 is spring-biased toward the lowered position as shown in FIG. 8 wherein the forward portion of the rocker is against the floor with the rearward portion being rocked upwardly therefrom and whereby the axles 77 are abutted against the uppermost boundaries of the openings 78. In the present example a pair of normally straight coil springs 82 are bent into a J shaped and disposed between block 73 and the back end surface 7 of the rocker 76. One end of the springs 82 is attached to top plates 74 by suitable fastening means 83 and the opposite ends of the springs are fastened to the back of the rocker 76 by suitable means 84. The tendency of the springs 82 to assume a straight position thus urges the rocker 76 to the described lowered position.
Considering now the operation of the ramp assembly 71, the springs 82 position the rocker 76 in the lowered position when the bed itself is lowered. During the final portion of the raising motion of the bed, the roller wheels 22 at the foot of the bed ride up on the top ramp surfaces 81 of the rockers causing a rocking motion thereof along the curved undersurfaces 79 into the position illustrated in FIG. 9. During this rocking movement of rocker 76 the axles 77 ride down and rearwardly along the lower bounding surfaces of the openings 78 to the lowermost portion thereof. At the completion of this movement the forward tip of the rocker 76 has risen and the portion of ramp surface 81 in contact with wheel 22 has assumed a more level orientation whereby most of the weight of the bed is borne by the rockers 76 reacting against the floor 57. The force exerted on the rockers 76 by the weight of the bed at this time does not have any sizable component in a direction which would tend to rock the rocker back and carry the foot of the bed outward from wall 23'.
When the motor is subsequently restarted to lower the bed, rocker 76 automatically shifts in a reverse fashion by a rocking motion along the undersurface 79. This results in part from the inclination of the guide tracks 36 and 44 in that the force exerted on the rocker by the motor is to some extent directed outwardly from wall 23'. This rocker motion, which is aided by springs 82, releases the foot of the bed and initiates the desired outward travel of the wheel 22 away from the wall 23'. Thus the return motion of the bed to the lowered position is accomplished smoothly without any manual operations other than the actuation of a switch. It may be noted that during the return motion of the rocker 76, axles 77 thereof ride upward and forward along the upper boundaries of the associated openings 78 until the rocker assumes the lowered position described above and illustrated in FIG. 8.
Considering now still other aspects of the invention, the headboard 18 is of an articulated construction with a joint being provided thereacross substantially at the level of the upper surface of the mattress 13. For this purpose, as shown in FIG. 2, the principal portion of the headboard 18 may be joined to a lower headboard portion 18' by a hinge means 86 which provides for pivoting of the principal portion of the headboard to a position overlying the head end Of the mattress 13. To hold the headboard 18 in this pivoted position, sidewardly extending tabs 87 may be provided thereon and an L-shaped clamp 88 may be pivoted at one end to each side frame member 16 whereby it may be swung up to engage the corresponding headboard tab 87. When the bed is lowered, clamps 88 may be swung back to release the headboard 18 which may then be pivoted to its upright position as shown in FIG. 1 and at which the tabs 87 rest against the lips 34 of housing 27. To avoid unwanted pivoting of the headboard 18 when in its raised position suitable spring catches 89 may be provided on the housing 27 to engage the tabs 87. If desired the hinge joint 86 in the headboard can be located to provide for retention of pillows and the like between the headboard and the mattress 13 when in the clamped position. However, this is often unnecessary in that it is a very simple matter to remove pillows particularly where the bed is arranged as hereindescribed in that a portion of the alcove 24 may be used for convenient storage of pillows.
The folding headboard 18, acting through mattress 13, serves to hold the relatively rigid box spring 12 in place during raising and lowering of the bed if the box spring is not otherwise secured to the bed frame 14 by screws or the like. However the mattress 13 may not be securely held by the headboard particularly if no footboard 17 is used. Referring now to FIGS. 1 and 10 in conjunction, a fabric mattress sack 91 may be utilized to hold the mattress 13 in place. Sack 91 has a configuration conforming generally to that of the mattress 13 except that it is open at the head end 92 to provide for an insertion of the mattress therein. In the present example the sack 91 has sides formed by spaced apart parallel straps 93 extending between the top portion 94 and bottom portion 96 of the sack although the sides may be formed by solid sections of fabric if desired. The top and bottom por tions of the sack 94 and 96 respectively may be essentially one continuous sheet of fabric which extends around the foot end of the mattress 97. To secure the mattress in position, a rectangular fabric flap 98 extends from the head end of the lower portion '96 of the sack and is wrapped around the head end of the box spring 12 and extends back for a distance thereunder between the box spring and the side frame members 16 of the bed. The above described retracting bed structure of FIGS. 1 to 10 may be modified in various ways while retaining basic features of the invention. FIGS. 11 and 12, for example, illustrate a modified ramp mechanism 71' for supporting the weight of the raised bed and for automatically releasing the bed and carrying the foot thereof downwardly and outwardly when the motor is reversed to lower the bed. In this modified construction, an inclined ramp surface 81 which may have a curvature similar to that previously described is defined by two separate ramp components which include a fixed ramp member 101 defining the lower initial portion of the ramp surface and a pivotable ramp member 101 defining a smaller subsequent portion of the ramp surface at the end thereof closest to the wall 23'. Fixed ramp member 101 is disposed against floor 57 between two parallel modified brackets 72 which extend outward from wall 23' at either side of a mounting block 73 thereat. Fixed ramp 101 is secured to the brackets 72 while the pivoting ramp member 102 is coupled thereto by axles 103 which provide for a pivoting move ment of ramp member 102 between the two positions illustrated in FIGS. 11 and 12, respectively. At the first position, as illustrated in FIG. 11, pivoting ramp member 102 contacts fixed ramp member 101 to define the continuous curved ramp surface 81' in conjunction therewith. At the second position of the pivoting ramp member 102, as illustrated in FIG. 12, the upper surface 81" of the pivoting ramp member has separated from the corresponding surface 81' of the fixed ramp member and has moved towards a more level orientation but does not pivot to the extent of actually reversing the inclination of the ramp surface 81". The pivoting ramp member 102 is urged towards the first position by springs 82 which are deformed into a J shape as hereinbefore described and which are situated between the pivoting ramp member 102 and block 73, the springs being attached to a top plate 74 by fastening means 83 and to the pivoting ramp member by fastening means 84 as in the first described embodiment of the invention. A stop 105 defines the limit of rearward movement of ramp member 102.
In operation, springs 82 cause the pivoting member 102 to assume the first or forward position as illustrated in FIG. 11 when the bed is lowered. As the bed is being raised in the manner previously described, the wheel 22 at the corresponding side of the foot of the bed rides up the ramp surface 81' of fixed ramp member 101 and onto the ramp surface 81" of the pivoting member 102. As the wheel 22 passes along surface 81", the weight of the bed pivots the ramp member 102 into the second or back position thereof as illustrated in FIG. 12. Bed movement then stops by deactuation of the motor as hereinbefore described leaving most of the weight of the bed supported by the pivoting ramp member 102 rather than being suspended from the lift mechanism to any sizable extent. When lowering of the bed is commenced by reversed energization of the motor, the force applied to the pivoting ramp member 102 through wheel 22 has a sizable component directed outwardly from wall 23 and the ramp member 102 is accordingly pivoted back to the first position as illustrated in FIG. 11, the movement being aided by the force of springs 82. This movement smoothly carries the foot of the bed downward and out- Ward from the base of the wall 23' along the inclined ramp surfaces 81" and 81' thereby avoiding the hereinbefore described adverse effects which might otherwise occur as lowering of the bed is initiated.
FIG. 13 illustrates still another form of automatic mechanism for relieving reactive forces on the lift mechanism when the bed is in raised position, and which automatically releases the bed and carries the lower end thereof downward and outward when the motor is re-energized to lower the bed. In this embodiment a fixed ramp 104 is disposed at the floor 57 and wall 23' in position to receive the roller wheel 22 at the foot of the bed as the bed approaches its uppermost limit of travel. To avoid difliculties in connection with the initial downward move ment of the bed ramp 104 is provided with a ramp surface 106 which is steeply inclined at the point contacted by roller wheel 22 when the bed is in its most elevated position and which is preferably of a diminishing inclination outwardly from wall 23' to provide for a smooth downward and outward motion of the foot of the bed. As hereinbefore discussed, a steeply inclined ramp of this kind facilitates the initial lowering movement of the bed but does not by itself act to relieve the lift mechanism of the force generated by the weight of the bed when it is in its elevated position. In the present embodiment the latter function is provided for by an automatic brake mechanism 107 which in elfect immobilizes the wheel 22 whenever the drive motor 53 is de-energized.
The brake mechnism 107 in the present example is secured to the underside of bed frame side member 16 and is comprised of a solenoid coil 108 of the type having an armature 109 which projects from both ends of the coil. The coil 108 and armature 109 are aligned in parallel relationship with the frame member 16 and a wedgeshaped brake shoe 111 is carried on the end of the armature adjacent roller wheel 32. Thus movement of the armature 109 toward the wheel 22 drives the shoe 111 against the rim of the wheel within the U-shaped leg 21 which carries the wheel. A compression spring 113 is disposed between the opposite end of armature 109 and a bracket 114 secured to frame member 16 to urge the armature and shoe 111 towards the above-described position at which the wheel 22 is immobilized and the weight of the bed is largely supported by ramp 104. Thus the brake mechanism 107 is in an actuated condition except when the solenoid coil 108 is energized to retract armature 109 and shoe 111 against the force of the spring 113.
To provide for automatic operation with respect to releasing the brake 107 when the motor is energized to either raise or lower the bed, circuitry is provided to energize the solenoid 108 simultaneously with the energizing of the drive motor 53. If the motor 53 is operated as previously described by current provided through a control switch 66 and upper and lower limit switches 68 and 69, respectively, the solenoid coil 108 may be connected across the common conductor 62 and the conducting path 116 between fuse 67 and switch 66, with a set of normally open relay contacts 117 being provided in the solenoid circuit. To close the relay contacts 117 and thus energize solenoid 108 at such times as the motor 53 is energized, the conducting path 116 may include a drive coil 118 which operates the relay contacts. Thus relay contacts 117 are closed at any time that the motor 53 is operating to move the bed in either direction.
The above described arrangement wherein the brake mechanism is in its actuated condition when the solenoid 108 is de-energized is preferable to a reverse arrangement in that no power is consumed except when the bed is in the process of being raised or lowered. Further, this arrangement provides a degree of fail safety in that the bed is immobilized if a power failure occurs when the bed is in its raised position.
It will be apparent that an automatic brake mechanism may be situated at other points in the bed construction and achieve somewhat similar results. The automatic brake may, for example, be associated with the previously described lift guide members 37, the lead screw 44 or may be situated at the drive motor 53 itself. The disposition of the brake at roller wheels 22 as hereinbefore described has the advantage of relieving stresses on more of the lift and guide mechanism when the bed is in the raised position and in addition, immobilizes the roller wheel 22 when the bed is fully lowered to help stabilize the bed.
FIG. 14 illustrates still another form of mechanism for automatically supporting and releasing the lower end of the raised bed without violent motions, stalling or other undesirable effects. In this embodiment, a fixed ramp member 119 is again disposed at the floor 57 adjacent wall 23' to receive a roller wheel 22 at the foot of the bed as the bed approaches the fully raised position. The fixed ramp 119 in this instance has a ramp surface 121 which presents a reversing curvature as the wheel 22 approaches wall 23'. In particular the initial portion of the ramp surface encountered by the wheel has a slightly concave curvature which progresses smoothly into a slightly convex curvature at the uppermost point of travel of the wheel whereby when the wheel comes to rest with the bed in the fully raised position the ramp surface immediately underlying the wheel has an almost level orientation thus supporting the weight of the bed without risk of a backward movement of the bed down the ramp which would apply reaction force against lift system. The ramp 119 further has a steeply inclined face surface 122 at the end of ramp surface 121 against which the wheel 22 impacts to define the limit of the travel thereof.
As has been previously discussed, a surface which is level or near level orientation below the wheel 22 provides for supporting the weight of the bed and relieving the lift system of reaction forces when the bed is raised, but in the absence of further provisions does not facilitate the initial downward and outward movement of the base of the bed when it is to be lowered. Such movement is facilitated in this embodiment of the invention by making use of a specialized resilient construction for the roller wheel 22. In particular, the roller wheel 22' is resilient in the radial direction. This property may be imparted to the wheel 22', for example, by constructing the wheel of a hub 123, which is journalled to the leg 21 at the foot of the bed by an axle pin 124, and a rim 126 of substantially larger diameter. To couple rim 126 to hub 123 in the desired resilient manner, a plurality of compression springs 127 extend therebetween, the springs being equi-angularly spaced around the axis of the wheel and being aligned along radii thereof.
The radial resiliency of the modified roller wheel 22' provides for smooth easy starting of the downward motion of the bed notwithstanding that the portion of the ramp surface 121 immediately underlying the wheel at this time is of a near level orientation. This results in that the initial steeply downward thrust on the wheel by the motor drive system is momentarily absorbed by the compression of the spring 127' which is most directly below the pivot axle 124 of the wheel at that particular time so that the actual movement of the axle and thus the movement of the lower end of the bed as a whole is directed more steeply downward than the underlying ram surface. The lower end of the bed thus moves at this time as if it were actually on a much more steeply inclined ramp. A rolling motion of the wheel 22' also commences at this time to carry the base of the bed outwardly from wall 23 and this motion is aided by the rebound of the particular spring 127' which was compressed by the initial movement inasmuch as such spring is immediately moved by the rolling motion of the wheel 22' to an orientation at which the spring force has a component directed horizontally. Once the rolling motion is smoothly initiated in this manner, the roller 22' reaches the adjacent more steeply inclined area of the ramp surface 121 thereby further facilitating the initial downward movement of the bed.
Thus while the invention has been described with respect to certain specific embodiments, it will be apparent that many variations and modifications are possible.
What is claimed is:
1. Mechanism for manipulating a retracting bed between a lowered horizontal position and a raised sub stantially upright position, comprising:
upwardly extending guide means having a lower end disposed adjacent a first end of said bed when said bed is in said lowered position thereof;
at least one movable member pivotally attaching said first end of said bed to said guide means whereby said first end of said bed may be raised along said guide means to draw the opposite end of said bed toward the base of said guide means; and
a drive motor for selectively raising and lowering said first end of said bed along said guide means.
2. Mechanism for manipulating a retracting bed as defined in claim 1 wherein said guide means is comprised of at least one linear track of hollow cross-section and having a slot extending along the side thereof facing said bed and wherein said lead screw is disposed within said hollow track, said movable carriage extending through said slot to engage with said lead screw.
3. Mechanism for manipulating a retracting bed as defined in claim 1 further comprising a housing having side members extending upwardly at each side of said guide means, and a vertically extensible and retractable screen fastened to the upper portion of said housing concealing said guide means when said bed is lowered therealong, said screen being fastened to said first end of said bed whereby said screen is automatically retracted and extended as said bed is raised and lowered.
4. Mechanism for manipulating a retracting bed as defined in claim 1 wherein said bed is characterized by a box spring and suprajacent mattress, further comprising a mattress sack within which said mattress is disposed, said sack having a flexible flap at the end situated at said first end of said bed, said flap extending downwardly along the adjacent end of said box spring and extending for a substantial distance along the under side thereof.
5. Mechanism for manipulating a retracting bed as defined in claim 1 wherein said upwardly extending guide means are inclined in a direction which forms an obtuse angle with respect to the bed when the bed is in the lowered position and further comprising a ramp at the base of said guide means for supporting said bed in the raised position thereof.
6. Mechanism for manipulating a retracting bed as defined in claim 1 further comprising means reacting to the initiation of downward movement of said bed by said motor to urge said opposite end of said bed outwardly from said base of said guide means.
7. Mechanism for manipulating a retracting bed as defined in claim 4 wherein a roller wheel is disposed beneath said opposite end of said bed for supporting said opposite end of said bed, and wherein said ramp has an inclined surface up which said roller wheel travels as said bed approaches said raised position thereof, said surface of said ramp having a final portion upon which said roller rests when said bed is in said raised position thereof, said final portion of said surface being less steeply inclined than an adjacent portion thereof.
8. Apparatus for raising and lowering a bed comprising:
means for guiding a first end of said bed upwardly and downwardly along a steeply inclined path of travel 12 whereby the opposite end of said bed moves horizontally towards the base of said path of travel and away therefrom; a roller wheel supporting said opposite end of said bed; a drive motor for raising and lowering said first end of said bed along said path of travel; and
support mechanism defining a ramp surface positioned to receive and elevate said wheel as said bed approaches the raised position thereof and having an element movable between a first position at which said wheel remains on said ram-p surface and is supported thereby and having a second position at which said wheel is urged outwardly from said base of said path of travel, said element being shifted automatically from said first to said second position concurrently with initiation of downward motion of said bed by said motor.
9. Apparatus for raising and lowering a bed as defined in claim 8 wherein said mova-ble element is a rocker defining said ramp surface and having a curved undersurface whereby said rocker rocks toward said path of travel as said roller wheel rides up the ramp surface thereby decreasing the inclination of hte area of said ramp surface which is contacted by said wheel when said bed is in the fully raised position.
10. Apparatus for raising and lowering a bed as defined in claim 9 wherein said ramp surface and said undersurface of said rocker both have an increasing curvature toward the end thereof adjacent said path of travel.
11. Apparatus for raising and lowering a bed as defined in claim 9 further comprising spring means acting on said rocker to urge said ramp to rock away from said path of travel of said first end of said bed.
12. Apparatus for raising and lowering a bed as defined in claim 9 wherein said rocker has co-axial axles projecting from each side thereof, said apparatus further comprising a pair of fixed brackets each being disposed at an opposite side of said rocker and each having a substantially elliptical opening for receiving the axle at the adjacent side of said ramp to define the limits of the motion of the rocker.
13. Apparatus for raising and lowering a bed' as defined in claim 8 wherein said support mechanism has a fixed ramp component defining the portion of said ramp surface which is initially contacted by said wheel as said bed approaches the raised position and wherein said support mechanism has a second ramp component defining the subsequent portion of said ramp surface which second component is movable in response to forces exerted thereon by said wheel, said second ramp component having a first position at which said subsequent portion of said ramp surface is contiguous with said first portion thereof and having a second moved position at which said subsequent portion of said ramp surface is moved away from said first portion thereof to be of reduced inclination.
14. Apparatus for raising and lowering a bed as defined in claim 8 wherein said movable element comprises a brake actuated by de-activation of said motor to hold said bed in the raised position.
15. Apparatus for raising and lowering a bed as defined in claim 14 wherein said brake is operative on said roller wheel and has a spring exerting a force clamping said wheel against rotation, said brake further having electrical means for counteracting the force of said spring and releasing said wheel, said electrical means being energize-d concurrently with energization of said motor.
16. Apparatus for raising and lowering a bed as defined in claim 8 wherein said wheel has a hub portion and a rim portion connected by resilient means whereby said rim is movable in a radial direction relative to said hub in response to a downward force on said wheel resulting from actuation of said motor.
17. Apparatus for raising and lowering a bed as defined in claim 16 wherein the area of said ramp surface contacted by said radially resilient wheel becomes less steeply inclined as said bed reaches the uppermost position thereof.
18. In combination with a retracting bed having one end which may be raised along a steeply inclined path of travel to draw the opposite end along the fioor toward the base of said path of travel, bed support mechanism defining a ramp surface at said base of said path of 10 thereon and movable in response to a downward force on said bed which is directed along said inclined path of travel to carry said bed back down said ramp surface.
References Cited UNITED STATES PATENTS 1,642,140 9/1927 Cane et a1 5-322 1,542,766 6/1925 Hall 5-133 3,340,549 9/1967 Billerbeck 5 335 CASMIR A. NUNBERG, Primary Examiner U.S. Cl. XtR. 5--10, 133